diff options
Diffstat (limited to 'lib/lzo/lzo1x_decompress_safe.c')
| -rw-r--r-- | lib/lzo/lzo1x_decompress_safe.c | 75 |
1 files changed, 52 insertions, 23 deletions
diff --git a/lib/lzo/lzo1x_decompress_safe.c b/lib/lzo/lzo1x_decompress_safe.c index a1c387f6afba..6d2600ea3b55 100644 --- a/lib/lzo/lzo1x_decompress_safe.c +++ b/lib/lzo/lzo1x_decompress_safe.c @@ -46,11 +46,23 @@ int lzo1x_decompress_safe(const unsigned char *in, size_t in_len, const unsigned char * const ip_end = in + in_len; unsigned char * const op_end = out + *out_len; + unsigned char bitstream_version; + op = out; ip = in; if (unlikely(in_len < 3)) goto input_overrun; + + if (likely(*ip == 17)) { + bitstream_version = ip[1]; + ip += 2; + if (unlikely(in_len < 5)) + goto input_overrun; + } else { + bitstream_version = 0; + } + if (*ip > 17) { t = *ip++ - 17; if (t < 4) { @@ -154,32 +166,49 @@ copy_literal_run: m_pos -= next >> 2; next &= 3; } else { - m_pos = op; - m_pos -= (t & 8) << 11; - t = (t & 7) + (3 - 1); - if (unlikely(t == 2)) { - size_t offset; - const unsigned char *ip_last = ip; + NEED_IP(2); + next = get_unaligned_le16(ip); + if (((next & 0xfffc) == 0xfffc) && + ((t & 0xf8) == 0x18) && + likely(bitstream_version)) { + NEED_IP(3); + t &= 7; + t |= ip[2] << 3; + t += MIN_ZERO_RUN_LENGTH; + NEED_OP(t); + memset(op, 0, t); + op += t; + next &= 3; + ip += 3; + goto match_next; + } else { + m_pos = op; + m_pos -= (t & 8) << 11; + t = (t & 7) + (3 - 1); + if (unlikely(t == 2)) { + size_t offset; + const unsigned char *ip_last = ip; - while (unlikely(*ip == 0)) { - ip++; - NEED_IP(1); - } - offset = ip - ip_last; - if (unlikely(offset > MAX_255_COUNT)) - return LZO_E_ERROR; + while (unlikely(*ip == 0)) { + ip++; + NEED_IP(1); + } + offset = ip - ip_last; + if (unlikely(offset > MAX_255_COUNT)) + return LZO_E_ERROR; - offset = (offset << 8) - offset; - t += offset + 7 + *ip++; - NEED_IP(2); + offset = (offset << 8) - offset; + t += offset + 7 + *ip++; + NEED_IP(2); + next = get_unaligned_le16(ip); + } + ip += 2; + m_pos -= next >> 2; + next &= 3; + if (m_pos == op) + goto eof_found; + m_pos -= 0x4000; } - next = get_unaligned_le16(ip); - ip += 2; - m_pos -= next >> 2; - next &= 3; - if (m_pos == op) - goto eof_found; - m_pos -= 0x4000; } TEST_LB(m_pos); #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) |